Operator’s Manual
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15
Common Mode Rejection Ratio
The performance shown in the graph below is typical performance with the 1x tip connected to
the HVFO108 and the black Reference and blue Signal leads twisted together.
•
The (LF Sweep) was measured with a low-bandwidth, high-voltage generator.
•
The (MF Sweep) was measured with a dual stage low-bandwidth, high-voltage
generator.
•
The (HF Sweep) was measured with an external generator.
All discontinuities are due to a combination of noise floor limitations of the measurement device
and amplification capabilities of the generators.
CMRR for the 5x, 20x and 40x tips can be expected to scale proportional to the tip attenuation
ratios. For instance, for a 5x tip, the CMRR will be 20log
10
(5/1) = 14dB less than shown above
(i.e., ~126 dB instead of 140 dB from 100 Hz to 100 kHz).
-180
-160
-140
-120
-100
-80
-60
-40
-20
0
10
100
1
10
100
1
10
100
CMR
R (
dB
)
Frequency (MHz)
Common Mode Rejection Ratio with 1x Tip
HF Sweep
LF Sweep
LF Sweep
LF Sweep
MF Sweep